OSU researchers fix calculation error in study on fracking and human health


CORVALLIS, Ore. – A 2015 Oregon State University study that linked natural-gas fracking to increased air pollution and heightened health risks has been corrected by its authors.

The corrected article still concludes that natural gas extraction contributes polluting chemicals known as polycyclic aromatic hydrocarbons (PAHs) to the air, but at levels that would not be expected to increase lifetime cancer risk above the EPA threshold.

The researchers measured levels of airborne PAHs near several Ohio hydraulic-fracturing sites in 2014. PAHs have been linked to increased risk of cancer and respiratory diseases.

In their March 2015 article, published in the journal Environmental Science and Technology, the researchers reported that PAH pollution from fracking could put a person living in the study area at a greater than a one-in-a-million risk of developing cancer during his or her life. One in a million is the threshold set by the U.S. Environmental Protection Agency for unacceptable cancer risk.

The authors retracted the article on June 29, 2016, after they found an error in a complicated spreadsheet used to calculate the concentrations of various PAH chemicals in the air.

The researchers redid the calculations and submitted a corrected version of the article, which was published on July 11, 2016. It finds that the estimated risk for the maximum exposure to fracking-related PAH pollution in the study area is 0.04 in a million—well below the EPA’s threshold.

Steve Clark, OSU’s vice president for university relations, said the mistake came to light as the researchers were crunching numbers from a current project. In the process, he said, they discovered a similar calculation error in a 2014 study of PAH pollution of air and water during the 2010 Deepwater Horizon oil spill, which also was published in Environmental Science and Technology.

That article too was retracted on June 29, and the corrected article was published online on July 8.

“In both cases the researchers were using a complicated, multi-linked spreadsheet to analyze large quantities of data,” said Clark. “The error was an honest mistake that unfortunately slipped through the peer-review process. Our researchers knew they couldn’t let it stand, so they stepped forward and corrected the error.”  

The coauthors of the Ohio fracking study include OSU researchers Kim Anderson (College of Agricultural Sciences) and Laurel Kincl (College of Public Health and Human Sciences), and Erin Haynes of the University of Cincinnati. Anderson also coauthored the Deepwater Horizon study.

College of Agricultural Sciences

About the OSU College of Agricultural Sciences: The college contributes in many ways to the economic and environmental sustainability of Oregon and the Pacific Northwest. The college's faculty are leaders in agriculture and food systems, natural resources management, rural economic development research, environmental toxicology and human health research.